Tattoos are the emblems of our age. They bristle from the biceps of men in summer shirts, from the lower backs of women as they ascend stairs, from the shoulders of basketball players as they drive toward the basket, and from every inch of certain celebrities. The tattoo is the battle flag of today in its war with tomorrow. It is carried by sure losers.

About 40 percent of younger Americans (26 to 40) have tattoos. About 100 percent of these have clothes they once loved but now hate. How can anyone who knows how fickle fashion is, how times change, how their own tastes have "improved," decorate their body in a way that's nearly permanent? I don't get it.

Johnny Depp once had "Winona Forever" tattooed on his shoulder but changed it to "Wino Forever" when his relationship with Winona Ryder turned out to last somewhat short of "forever." Angelina Jolie once sported the name "Billy Bob," for Billy Bob Thornton, but, since she began a relationship with Brad Pitt, has had it replaced with the global coordinates of her children's birthplaces. She is also emblazoned with the legend "Know Your Rights." The British writer Simon Mills likens that to a sign hung in small-claims court.

David Beckham has turned his body into a billboard of Hebrew, Chinese and Hindi characters, not to mention a semi-nude representation of his wife. Victoria Beckham, the aforementioned semi-nude, is graffitied with Roman numerals and Hebrew lettering. As for the conspicuously tattooed Amy Winehouse, her lyrics bespeak an intelligence that someday -- if she has a someday -- will cause her to wonder why she never gave that day a thought.

I asked a college professor what she thought of tattoos, and she said that for young people, they represent permanence in an ever-changing world. But how is that possible? Anyone old enough and smart enough to get into college knows that only impermanence is permanent. Everything changes -- including, sweetie, that tight tummy with its "look at me!" tattoo. Time will turn it into false advertising.

The permanence of the moment -- the conviction that now is forever -- explains what has happened to the American economy. We are, as a people, deeply in debt. We are, as a nation, deeply in debt. The average American household owes more than its yearly income. We save almost nothing (0.4 percent of disposable income) and spend almost everything (99.6 percent of disposable income) in the hope that tomorrow will be a lot like today. We bought homes we could not afford and took out mortgages we could not pay and whipped out the plastic on everything else. Debts would be due in the future, but, with any luck, the future would remain in the future.

Here and there the occasional scold warned that all this was unsustainable. Social Security is underfunded. The government ought to -- just occasionally -- balance its books. But for a long time, the unsustainable seemed sustainable. The immutable rules were mutable. Virtually the entire political establishment insisted that tomorrow would never come. Republicans joined with Democrats in never calling in a loan. Who says bipartisanship is dead? Not when it comes to fiscal irresponsibility.

I recall a tiny scandal of some years back when it was alleged that George Shultz, then secretary of state, had a tattoo of a tiger on the nether reaches of his body. This was credible because Shultz had gone to Princeton, where such tattooing was once customary for undergrads, although not, I hope, for the faculty. (I am thinking now of Einstein.) I also know a Navy man who had a bicep done in World War II, not that it stopped him from becoming executive editor of The Post. I withhold his name out of consideration for his family.

But the tattoos of today are not minor affairs or miniatures placed on the body where only an intimate or an internist would see them. Today's are gargantuan, inevitably tacky, gauche and ugly. They bear little relationship to the skin that they're on. They don't represent an indelible experience or membership in some sort of group but an assertion that today's whim will be tomorrow's joy. After all, a tattoo cannot be easily removed. It takes a laser -- and some cash.

I have decades' worth of photos of me wearing clothes that now look like costumes. My hair has been long and then longer and then short. My lapels have been wide, then wider, then narrow. I have written awful columns I once thought were brilliant and embraced ideas I now think are foolish. Nothing is forever.